I am trying to finally put my Palm TX into retirement, but there are still things I do on it for which I have not found adequate replacements. The most important right now is a way to store encrypted text files to keep my passwords on. I would prefer a program that stores data in regular text files that are encrypted at "save" time and unencrypted at "load" time. I do not mind an app that uses a proprietary data format IF I can either import and export to standard text files through "load/save" options, OR if I can use "select/copy/paste" through a common clipboard function
(through the system).

I need a program where I can trust that the creator will still be around to maintain it, say, 10, 20, 30 YEARS from now (I think I used the same Palm program for around 20 years). Or it should be fully open sourced.

Any thoughts or advice would be appreciated.